Drafting pen



March 31, 1970l E. BoK

DRAFTNG PEN Filed Sept. 2, 1968 United States Patent O 3,503,693QRAFTING PEN Edward Bok, Falls Church, Va., assignor to Dike, Inc.,Washington, D.C., a corporation of the District of Columbia Filed Sept.26, 1968, Ser. No. 762,844 Int. Cl. B43k 1/10 U.S. Cl. 401--259 ClaimsABSTRACT 0F THE DISCLOSURE A means for simultaneous ink reservoirVent-control and control of the movements of the used cleaning wire instylographic drafting pens.

CROSS REFERENCES TO RELATED APPLICATIONS In drafting pens, Vent valveshave been disposed effectively in the upper portion of the ink reservoiras, for example, described in my patent application Ser. No. 697,433,filed Jan. 12, 1968, entitled Drafting Device and application Ser. No.759,001, filed Sept. 11, 1968, entitled Drafting Pen With Vent Valve.

A related improvement concerns the provision of a knob-operative stemthrough the interior of the drafting pen ink-reservoir, providingthereby improved cleaning media for the ink passageway in the tip of thedrafting pen, all as described in my patent application Ser. No.758,304, filed Sept. 9, 1968, and entitled Drafting Pen With ExtensibleTip; and in my patent applications Ser. No. 760,923, tiled Sept. 19,1968, entitled Drafting Pen; and Ser. No. 762,878, led Sept. 26, 1968,entitled Drafting Pen.

BACKGROUND OF THE INVENTION Field of the invention Contemporary draftingpens include for the most part a cylindrical hard metal tip and aclearing needle extending from the reservoir axially of the tip. Theneedle usually has a weight seated in the reservoir, so that a jerkingmovement of the pen will unseat the weight and actually reciprocate theneedle Within the ink-flowing capillary passage which extends from thereservoir through the cylindrical pen tip. This reciprocation of theneedle clears the passage of crystallized ink permitting a normal inkflow during drawing. According to such pen structures the clearingneedle can be extended or retracted within the cylindrical pen tip to avery small degree only. As a result, it is not possible to completelyclear the capillary passage of crystallized ink.

Description of the prior art The prior art devices have includedmechanisms for extending and retracting the needle within the pen tip.However, the degree of extension or retraction has been slight and therehas not been a positive means for clearing the capillary passage. SeeBuschle (2,805,645). In this device the crank shaft 6 and guide rod 3are provided for reciprocating needle A within the pen tip 1.Reciprocation of the needle is limited to the extent of the offset 6 inthe crank shaft and there is not provided a positive means forautomatically retracting the needle.

See also Cholet (2,878,783). Here needle 23 is simply used as a sealingmechanism and there is not provided any means for longitudinallyreciprocating needle 23 within the pen tip to the extentthatcrystallized ink may be completely removed. Also there is notprovided any means for automatically withdrawing the needle as it isdesired to write.

In the patent application (Ser. No. 697,433), entitled 3,503,693Patented Mar. 3l, 1970 f. i ICC Drafting Pen and led by applicant hereinJ an. 12, 1968, a drafting pen is described whereby it is possible tohave the drafting pen placed on the sheet at an angle which is mostsuitable for the draftsman. This pen included the combination of a pentip and a guide or support which rested on the drafting sheet.Consequently, the pen tip was supported at an angle to the paper and theradial position of the pen tip with respect to the barrel was fixed.

In some drafting Work this more expensive construction is not required,especially if the quality of the drawn lines are of not too greatimportance. The possibility of supporting a drafting pen in a givenradial position and with only the pen tip resting upon the draftingpapers provides a big advantage over the existing drafting pens.

Furthermore, conventional stylographic drafting pens and also thedrafting pens as are described in the aforementioned patent application(Ser. No. 697,433), make use of a vent construction to the ink cartridgewhich is positioned in the bottom part of the pen underneath the inkcartridge. See Patent No. 2,891,512. In this type vent there are thedisadvantages of an easy clogging with dried ink in the vent opening andthe leakage of ink through the opening in the pen tip.

Other vent constructions are illustrated in Patent Nos. 1,319,556 and1,457,875 describing stylographic fountain pens, which are not suitablefor drafting straight lines, since the flow of ink around the pen tip isnot tolerated 'when using a ruler.

Patent 3,333,576 has an expensive buildup for a low priced drafting pen,having a pressurized seat for activating a cleansing wire in the absenceof any valving for the air vent.

In the drafting pen construction of Y. Wallace (2,214,494) the inner endportion of the pen tip is provided with a large bore 13 and the outerend with a smaller bore joining the larger bore in a conical bevelledportion 15. Here, as the pen is at rest, ink crystallization at the boreends is likely.

In my copending applications for Patent Ser. No. 759,001, tiled Sept.11, 1968, entitled Drafting Pen With Vent Valve; Ser. No. 760,923, iledSept. 19, 1968 and entitled Drafting Pen; and Ser. No. 762,878, liledSept. 26, 1968, and entitled Drafting Pen, a similar structure is shownand described, but the means facilitating venting and securing of thepen differ materially.

SUMMARY OF THE INVENTION According to the invention, the necessaryregulation of air admitted to the drafting pen ink reservoir iscontrolled by a spring-pressurized stem, which extends in constructionthrough the top of an ink reservoir contained within the pen.Simultaneously, this stem serves to impel a downward thrust to acleaning wire, to thereby provide a fast and complete cleaning of theink passageway in the pen tip. Both venting of reservoir and cleaning ofthe ink passageway are controlled by hand manipulation of a stemconnected knob. A pressure spring located in the ink reservoirunderneath the pen needle Weight serves to urge the cleaning wire to itsrest position inside the pen tip if no manual force is applied to thestem connected knob.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view ofa stylographic drafting pen, according to the invention showing cleaningwire, stem holder and attached knob in rest position;

FIG. 2 is an enlarged fragmentary vertical sectional view of the writingnib of the drafting pen according to FIG. 1;

FIG. 3 shows the Writing nib according to FIG. 2 with cleaning wire'forced downwardly to its lowermost position;

43 FIG. 4 is.the.writing nib according to FIGS. 2 and 3 showing cleaningwire in its uppermost position;

FIG. 5 is an enlarged horizontal sectional view of the holder assemblytaken along section lines 5 5 of FIG. 1;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Pen comprises barrel 12, havingink reservoir 14 and the writing nib 16 with the attached pen tip 18.Within, cleaning wire 20 is attached to the needle weight 22 and thereciprocable vent stem 24 is connected in turn to stem holder 26, all asshown in FIG. l. Ink reservoir 14 fits with its bottom 110 in the flatinterior 112 of barrel 12. The knob 28 of this stem holder 26 protrudesthrough the opening 30 in the side wall 32 of the barrel 12, and ismanually placeable in slot 30. Other knob constructions with the samefunction are also possible, as for instance, a knob representing a fixedextension of the stem holder 26, protruding through the top of thebarrel 12.

In operation, after initially filling reservoir 14 with ink 78, thewriting nib 16 may be secured leak free with its fiat sided nib seat 111against the bottom part 110` of the ink reservoir 14 (see also FIG. 5)by means of the threaded plug 50 engaging corresponding threads 98 ofthe barrel 12 and securing this nib in position without rotary angulardisplacement. Thus, one is given a pen tip 18, having an angular bottom60 which is at about 30, enabling the drafting pen to be advantageouslyheld at an angle of about 60 with respect to the drafting sheet. Needleweight 22 is longitudinally movable in the interior 60 of writing nib18, whereby the lock pin 106 prevents the slideable removal of theweight 22 during the disassembling of the pen 10 for filling purposes.(See FIGS. 4 and 5.) In the bottom interior 114 of the writing nib 16and underneath needle weight 22 the compression spring 116 is located.As is shown in FIGS. 1 and 2 with the knob 20 in its rest position theneedle weight 22 rests upon the expanded spring 116 with the bottom 68of cleaning Wire 20 retracted to the inside 84 of the pen up 1s. (FIG.3.)

In the interior 80 of the stern holder 26 the pressure spring 72 islocated, whereas in the top part 102 the opposed pressure spring 100 ispositioned. This combination of springs (FIG. 1) provides a variablecompression gap between stem holder 26 and ink reservoir 14, whereby inthe rest position of the knob 28 (FIG. l), the valve portion 118 of thevent stem 24 is fitted in the vent-opening 76 of the reservoir 14. Now,as the ink reservoir 14 is filled with ink 78, it is thus prevented fromleaking through closed opening 76, the same seal being effective as knob28 may be brought to its lowest position against shoulder 80, all asindicated by the lower phantom line knob position shown.

Again, in operation, if the stem knob 28 is moved upwards againstcompression spring 100 from its previous position of rest, to thelimiting shoulder 82, stem valve 118 is moved out of its opening 76,providing thereby ventilation of the ink reservoir 14 as may be requiredperiodically.

Bearing in mind the foregoing, as knob 28 is quickly retracted from itslowest position to its top position against shoulder 82, the stem 24 isremoved from needle weight 22, leaving the needle weight 22 free to moveupwards under the expanding force of pressure spring 116, resulting in atemporarily longitudinal displacement of the cleaning wire over thedistance as shown in FIG. 4 with the bottom 68 of the cleaning wire 20`retracted into ink chamber 104 and the Wire 20 surrounded by ink inliquid form. At the same time, this ink iniliquid form can and shouldleak from this chamber 104 into the ink passage 84. During succeedingforced downward 'movement of the cleaning wire 20 the now wet Wireforces ink in liquid form through the ink passage 84 and easily scrapesand removes dried ink and other foreign matter out of passageway 84.

vAgain, after a long period of non-use, flowing of ink through the inkpassage 84 may be achieved by downward displacement of knob 28 to itslowest position at shoulder 80, forcing thereby wire 20 downward toprotrusion beyond pen tip 18, `(FIG. 3). This may be followed a few'times by a succeedingupward movement of wire 20 by the urging force ofthe depressed vpressure spring 116, resulting in a sufficient looseninguntil it is possible to obtain a longitudinal displacement to the topposition of the wire 20 by means of the expanding force of the spring116 when the stem 24 and associated elements have been quickly andforcibly displaced to the uppermost position represented by FIG. 4.

With this unique construction of the drafting pen 10 no shaking isrequired to remove dried ink or other obstacles from the ink passage 84.

In the uppermost position 82 of the knob 28, the valve 118 is moved outof the vent opening 76 of the ink reservoir whereby there is no requiredlongitudinal jerking of the drafting pen, with no resultant flowing ofthe liquid ink 76 in the ink reservoir, avoiding thereby ink leakagethrough the opening 7-6. Only the stem extension 120 with a smallerdiameter as part of vent stem 24 protrudes through the opening 76 intothe ink reservoir to contact the needle weight 22. By means of this ventsystem, ventilation to ink reservoir 14 is possible 'without anydownward protrusion of cleaning wire 20 from pen tip 18, thus enablingan uninterrupted drafting of lines during this Venting period.

The pressure springs 72 and 116 may be given such a compression force intheir compressed position, and the weight 22 and the stem holderadjusted in weight and the pressure spring can be made so easilycompressible, that by manually loosening the knob 28 from its lowestposition, the whole combination of cleaning wire 20, needle weight 22,Vent stem 24, stem holder 26 and knob 28 may be automatically forced bythe expanding springs to their temporary topmost position. Consequently,Yonly manual downward movements of the knob 28 are then required toclean the ink passage 84. Furthermore, the pressure springs 72 and 116may be combined into one spring 116 with the achieving of the samedescribed results.

In the drafting of lines, the cleaning wire 20 does not touch thedrafting paper, thus no scratching of this paper occurs from scrapingmovement of this wire 20 over its surface. This yields best draftingresults.

I claim:

1. A self-cleaning, ventable writing pen, comprising in combination:

(A) a barrel to which is secured (B) a nib, said nib defining a penscrib'er channel at its free end; I

(C) a reservoir fixed within the barrel and being communicant withthenib, said reservoir being vented at its upper end; A

(D) a reciprocable valve stem, passing into said'rservoir and having avalular portion thereof engageable with the reservoir, said stem beingvariably compression seated with respect to the reservoir and havingmeans to dislocate said vstem extensibly with respect to said reservoir;

(E) a cleaning wire extending through sad channel and having weightmeans at its free end, said weight being alternately compressioncontacted by said stern for use in cleaning said channel by reciprocablemovement thereof;

(F) first compression means connecting vthe reservoir and stem; and

(G) second compression means in opposition to the first, said secondcompression means engaging the barrel and stern;

(H) third compression means seated in the nib against the weight means,urging the weight means and pen upwardly.

2. The drafting pen according to claim 1 wherein the stem includessuccessive portions of variant diameters, the lower portion being oflesser diameter than the upper portion, whereby the respective portionsalternately vent and seal the reservoir upon manipulation.

3. The drafting pen according to claim 2 in which stern and reservoirare complementally asymetric in at least one contiguous portion thereofto secure pen tip writing end and associated elements againstdisplacement.

4. The pen according to claim 2, in which the nib includes locking meansat one end to block movement of said cleaning wire out of said nib.

5. The writing pen according to claim 2 in which the nib channelincludes plural chambers, a first chamber being of substantially greaterdiameter than the pen and a second being slightly greater, the saidfirst being disposed to pass ink as the wire is retracted adjacent sameand the second being in extension thereof and adapted to cleaningcontact with the pen as it is reciprocated from the rst to the second,precedent to seating in extension of the second in writing.

6. The writing pen according to claim 5 in whirh the nib includeslocking means at one end to block movement of said cleaning wire out ofsaid nib.

7. A drafting pen comprising:

(A) a pen barrel;

(B) an ink reservoir of the type having an air vent and supported withinsaid barrel;

(C) a pen nib with a spirng biased and weighted cleaning wire movable inthe nib, the nib including a hollow ink capillary passage communicatingwith said ink reservoir and terminating in a tubular pen point;

(D) a spring pressurized stern, superposed with respect to saidreservoir within said barrel and including:

successive portions of variant diameters, one said portion being oflesser diameter than the other said portion, both said portions beingengageable with the ink reservoir whereby the respective portionsalternately vent and seal the reservoir upon manipulation;

(E) spring bias means engaging the stem exteriorly, said bias meansseating on said barrel whereby upon alternate retraction and ejection ofsaid stem, the hollow ink capillary passage will be cleaned, washed andsequentially scraped, precedent to further usage of said pen point.

8. The drafting pen according to claim 7 in which the nib includeslocking means at one end to block movement of said weighted cleaningwire out of said nib.

9. The drafting pen according to claim 8 in which the nib channelincludes plural chambers, a rst chamber being of substantially greaterdiameter than the pen and a second being slightly greater, the said rstbeing disposed to pass ink as the wire is retracted adjacent same andthe second being in extension thereof and adapted to cleaning contactwith the pen as it is reciprocated from the tirst to the second,precedent to seating in extension of the second in writing.

10. The drafting pen according to claim 9 in which the nib includeslocking means at one end to block movement of said cleaning wire out ofsaid nib.

References Cited UNITED STATES PATENTS 1,447,632 3/ 1923 Schmidt 401-2582,805,645 9/l957 Buschle 401-151 2,878,783 3/1959 Cholet 401--2582,891,512 6/1959 Kovacs 401-258 X 3,419,335 12/1968 Bok 401--260 XFOREIGN PATENTS 857,986 1/ 1961 Great Britain.

885,345 12/ 1961 Great Britain. 1,073,878 6/ 1967 Great Britain.1,131,287 10/1956 France.

LAWRENCE CHARLES, Primary Examiner

